Production of aldehyde sulfoxylates.



UNITED STATES 'PAEENT OFFICE.

. FRANZ BECKER, OF PRAGUE, AUSTRIA-HUNGARY, ASSIGNOETO BADISOHE ANILIN &SODA FABRIKQOF LUDWIGSHAFEN-ON-THE-RHINE, GERMANY, A CORPORATION.

PRODUCTIONOF ALnErrYnE SULFOXV-YLATES.

Patented April 21, 1908.

Application filed February 6, 1906. Serial No. 2519.783.

To all whom it may concern:

Be it'known that I, FRANzBEoKER, doctor of philosophy and chemist,subject of the Emperor of AustriaHungary, residing at Prague, inAustria-Hungary, have invented new and useful Improvements in, theProduction of Aldehyde Sulfoxylates, of which the following is aspecification.

My inventionrelates tothe production of aldehyde sulfoxylates.

A method is described in the Berichte dc?" Deutschen UhemischenGesellschaft Vol. 38, p. 1072, for the preparation of formaldehydesulfoxylates by reducing formaldehyde bisulfite with zinc dust andacetic acid (see also Letters Patent No. 793,610). I have now discoveredthat aldehyde sulfoxylates can be obtained easily and in good'yieldwithout it being necessary to have present during the reaction eitherany extraneous acid, or any alkali.

According to this invention I allow formaldehyde, zinc dust and abisulfite to react upon one another at a temperature raised above fortydegrees centigrade and, 'of course, instead of any of the above namedingredients an equivalent can be employed, for instance instead offormaldehyde, acetaldehyde can be employed, and instead-- of zinc usemay be made of any other metal, such for instance as iron, which has asimilar reducin action. Instead of a bisulfite, a hydrosu fite can beemployed and since, as is well known, aldehyde hydrosulfites behavechemically as if they were composed of equimolecular proportions ofaldehyde bisulfite and aldehyde sulfoxylate, the hydrosulfites are fullyequivalent to the bisulfites for the purposes of this invention.

In order to work up the products of the reaction, the mixture can, whensodium bisulfite is employed, be filtered in order to remove zinc andzinc hydroxid and the filtrate can be evaporated. When zinc bisulfite isthe compound to be reduced, the reaction mixture should preferably betreated finallywith, for instance, a sodium salt and then be filteredand evaporated.

The following examples will serve to further illustrate the nature of myinvention and how it can be carried into practical effect, but myinvention is not confined to these exam les. The parts are by weight.

' xample 1. Mix together one hundred (100) parts of a forty (40) percent. sodium bisulfite solution, eighteen (18) parts of a forty (40) percent. formaldehyde solution and thirty-five (35) parts of zinc dust, andboil the whole for two (2) hours. Filter off the zinc mud and evaporatethe filtrate, preferably in 'vacuo. In this way a whiteporcelain-likemass is obtained which is free from zinc, is not hygroscopic, and isstable in the air. The reaction that occurs can be represented by thefollowing equation:

NaHSO, CH O Zn H O NaHSO CH' O Zn (OH) 2 Example 2. Boil together, forfrom two (2) to three (3) hours, one hundred and eight (108) arts of atwent -two (22) per cent. zinc bisulfitesolution, teen (15) parts of aforty (40) er cent. formaldehyde solution in four hun red (400) parts ofwater, and

Zn (HSO3), 201-1 0 2Zn 2 (ZnSO xOH O) Zn 0H Subsequently on the additionof a sodium salt the double decomposition of the zinc salt to the sodiumsalt takes place.

Example 3. Boil together, for one (1) hour, fifty (50) parts of aforty-two (42) per cent. sodium bisulfite solution, twenty (20) parts ofa thirty (30) er cent. formaldehyde solution and twenty-t iree (23)parts of very finely divided iron powder containing about sixty percent. of free metallic iron. Filter off and wash the residue, whereupona solution of sodium formaldehyde sulfoxylate which is almost free fromiron is obtained and this can be evaporated in vacuo. The reaction thatoccurs can be represented by the following equation:

NaIIS O CH O Fe NaHSO,.CH,O FeO Now what I claim" is:

1. The process of producing aldehyde sulfoxylate by acting at atemperature above 40 C on a bisulfite with an aldehyde and with a metalwhich has a reducing action, while totally avoiding the presence ofextraneous acid.

2. The process of producing formaldehyde with zinc dust, while totallyavoiding the 10 sulfoxylate by acting at a temperature above presence ofextraneous acid. e0" C. on a bisulfite with formaldehyde and Intestimony whereof I have hereunto set with a metal which has a reducingaction, my hand in the presence of two subscribing 5 while totallyavoiding the presence of exwitnesses.

traneous acid. 4 FRANZ BECKER.

3. The process of producmg formaldehyde W itnesses: I sulfoxylate byacting at a temperature above ARTHUR SOHWEINBURG,

40 C. on a bisulfite with formaldehyde and ARTHUR SoHwERz.

